European Union Directive 94/45
In 1995, the European Union developed a food ingredient classification system. For caramel color, the EU adopted the four internationally recognized caramel classes as E150a, E150b, E150c, and E150d.
E150a PLAIN CARAMEL
E150b CAUSTIC SULPHITE CARAMEL
E150c AMMONIA CARAMEL
E150d SULPHITE AMMONIA CARAMEL